Looking at a freighter's cargo door design, I was surprised to find the door structure stuffed with insulation material, even though this is known to soak with water in flight and weigh down the aircraft, which doesn't carry passengers with comfort requirements at all.
The reason, I was told, was that the insulation "reduces the amount of water that falls on the guy opening the cargo door."

Is that correct? Is water draining from inside the door structure a problem when you open the cargo door on the ramp?

Most cargo doors that I've seen have minimal amounts of insulation in them, though rain collection on the interior structure of the door seems to be less of an issue than water entering the cargo area and dispersing into areas other than intended drain ports. As far as the guy on the ground, if he's standing in the right position, he'll get drenched when the door closes from all that standing water on top of it. (Its a perfect place for the newbie)

-A properly designed and maintained door will not allow water into it.
-Any water that may get into a properly designed and maintained door will drain out through the drain holes, it will not accumulate.
-I don't recall seeing any insulation inside a door. The exception is a main cargo door on a convertible. If the aircraft may carry either pax or cargo, the main cargo door should be insulated.
-The lower door may have insulation as part of the liner, especially in a compartment that may hold live animals.

I've opened, literally, thousands of doors, main, lower and bulk, powered and unpowered, and never got soaked because of it.

Can't speak of main deck cargo doors, but the only water I've seen come out of a cargo door would be from a Boeing outward opening lower lobe cargo door. There is usually a cup or two of water that collects behind the seal depressor (not inside the door itself but at the bottom edge) after a flight, as the design creates a channel for the water to collect in, probably not meant to do that, but it happens anyways, which pours onto the ground when you open the door. The 747 is the worst offender, at least in my experience at UAL.

A few pallets of red wine which shifted in flight and broke a lot of bottles. Yes, I got drenched when opening the cargo door. Took forever before my work clothes stopped making me stink like a wino...

I thought I was doing good trying to avoid those airport hotels... and look at me now.

Quoting FredT (Reply 7):Yes, I got drenched when opening the cargo door. Took forever before my work clothes stopped making me stink like a wino...

Was your mouth open at that time When the MCD on a freighter is opened after it Arrives from a Destination that experienced heavy rain.A bit of water trapped near the Seal Depresser flows out.
regds
MEL

Not quite sure where the water collects when the main deck and lower doors is/are open, but I ALWAYS try to make sure that someone is standing underneath when I close it. Not enough to really piss someone off, but definitely enough to surprise them. Guess I have too much time on my hands huh?

When we'd offload Air China, and they happened to have a pallet of monkeys on board, whew! After that many hours locked up in the aft cargo pit, that was quite the odor, and it seemed to stick to everyone. I'd rather smell like a wino...